While the book has never had a sequel or spin-off (although it has been referenced in other Stephen King works), Carrie has already had a few times where people try to continue the book's story in terms of TV/Film.
After the 1976 film version, there was the sequel "The Rage: Carrie 2" which focused on a different girl - Rachel Lang - who was also the daughter of Ralph White and had developed Carrie's telekinetic powers.
The 2002 TV movie adaptation deliberately altered its ending so that Carrie would survive thanks to Sue, with the plan being for a follow-up TV series that would follow Carrie helping others with psychic powers. However, this materialized due to poor ratings. As for the 2013 adaptation, I'm not too sure.
The question I have is, if you could make a sequel to the book (be it another book, a TV show/special or a film), then what would you do?
(There's no right or wrong answers - this is purely a brainstorming session and an excuse to be creative).